Muli Ben-Yehuda's journal

Looks like there’s going to be another Xen summit in Austin in January. I wonder who else is going?

Oh yeah, one thing I wanted to write about: we went to see a play yesterday, “Six Dance Lessons in Six Weeks” (Hebrew review). It was surprisingly good, albeit somewhat depressing for a comedy. A bitter-sweet comedy, if you will. Great acting by Natan Datner.

We had balcony seats, so Orna brought along her bird-watching, field-grade binoculars. They were so good it was like being right there on stage. We could see every nuance, every facial expression, every wrinkle. Sometimes, a little blurriness is a good thing.

I was feeling really lousy this morning, then felt great for a few hours, and now I’m feeling lousy again. I’m sure there’s something I could do to regulate these wild mood swings, but I have no idea what.

I was going to write a bunch of other things, but I no longer remember what they were. Such is life.

It looks like I’m headed to the US again in a couple of weeks. I’m starting to get used to this.

Every great journey begins with a small step. Mine actually begins with two: a morning workout at home yesterday, and then a long overdue visit to the gym. While suffer^H^H^H^H^H^Hexercising on the treadmill, I listened to this CD to get in the mood. It worked.

On Friday I switched our home connection from ADSL to cable, since we’re getting cable practically for free from work and ADSL is decidedly non-free. I’ve been resisting this change for a while, since I have somewhat of an emotional attachment to ADSL, but Orna has been pushing for it and I gave up. Cable works quite well so far.

Then I continued working on the DMA mapping patch and after testing it on a bunch of machines sent the first version (-C1) to lkml.

In the evening we caught Kate and Leopold on TV, which was surprisingly enjoyable.

On Saturday, I woke up early and submitted a follow up Xen patch to this bug. The Cambridge guys committed both my and Jeremy Katz’s patches, so the follow-up reverted mine (Jeremy’s was much prettier). Then we drove to Tel Aviv for lunch at Orna’s sister’s and her boyfriend’s apartment. Lunch was highly enjoyable and their apartment is gorgeous.

In the afternoon we visited omerm and shapirac, and had a horribly geeky discussion. Much fun was had. shapirac mentioned that my PNS posts used to motivate her to work out, so mayhap I’ll resuscitate them. $DEITY knows I need the exercise.

When we got home Orna cooked an amazing dinner, and then I watched “quality TV”, aka The Wire. While watching (perhaps during the detective wake?) I realized that there was a way to eradicate one of the warts of the dma-mapping-ops patch.

The way I structured dma_xxx() is that they call a dma_mapping function if one exists, and otherwise call the default gart_xxx() function. This was done in order to keep the fast path fast (avoid a function pointer call). Unfortunately, for the nommu case, where no gart exists, this requires us to link in gart_xxx(), even though it’s never called. The solution is obvious, even if it did take me a week or so to come up with it – provide empty definitions of gart_xxx() if CONFIG_GART_IOMMU is not defined. While implementing it, I also discovered a couple of buglets – nommu_map_sg() and nommu_unmap_sg() were not getting called, and I erroneously removed a couple of EXPORT_SYMBOLS(). Fixed, tested, and released swiotlb-dma-mapping-ops-D1.

And that’s about it. How was your weekend, gentle reader?

What I did on the holidays: [RFC PATCH] clean up x86_64 DMA mapping dispatching. Also, various Xen bits.

Holy batman, I actually agree with Joel Spolsky!

The Kernel Korner articles in Linux Journal are usually pretty good. This month’s, however, discusses an in-kernel ftp server (signs of danger), does not check memory allocations and overwrites sys_call_table from a module. I stopped reading at that point.

Fourth Annual Workshop on Systems and Storage Technology
December 11, 2005
Organized by the IBM Research Lab in Haifa

You are cordially invited to participate in a one-day workshop on
Systems and Storage Technology, to be held on Sunday, December 11,
2005 at the IBM Research Lab in Haifa, located on the Haifa University
campus, Mount Carmel, Haifa, Israel.

This annual full-day workshop provides a venue for the research and
development communities from both academia and industry to share their
work, exchange ideas, and discuss issues, problems, works-in-progress,
and future research directions and trends.

This year’s workshop emphasizes the concepts of virtualization and
scale-out that have recently become hot topics in the IT industry.

Virtualization is a collective term used for software and hardware
technologies that aim at consolidating organizational computing
resources, often heterogeneous and scattered over multiple physical
locations, into a unified computing infrastructure. A virtualized
system facilitates resource sharing and management, thus improving
utilization and operational costs. Virtualization seeks to present
computing resources so that users and applications can easily benefit
from them, rather than presenting them in a way dictated by their
implementation, geographic location, or physical packaging. In other
words, virtualization provides a logical rather than physical view of
data, computing power, storage capacity, and other resources.

Scale-out computing leverages the pay-as-you-grow hardware acquisition
model. Its goal is to facilitate seamless integration of newly
acquired components into existing systems, and optimize the
utilization of those components for better load balancing, high
availability, and workload partitioning.

Topics of interest include, but are not limited to, the following
subjects:

• Server virtualization
• Virtualization and scale-out technologies (networking, blade centers, VMware, etc.)
• Server migration
• Remote deployment
• Remote software distribution and upgrade
• Clustering for virtualization and scale-out
• Scale-out and virtualization in grid computing
• Storage virtualization
• Network virtualization
• Virtualization through Web services
• High availability
• System and network management
• Autonomy and self-management: self-healing, self-protection, self-configuration, self-optimization, etc.
• Interfacing to virtualized systems and services (ubiquitous
  computing)

The workshop will take place in the auditorium (room L100) of the IBM
Research Lab in Haifa. A detailed agenda and participation information
will be distributed at a later date. The official language of the
workshop is English.

Please feel free to distribute this invitation to students and fellow
researchers/developers.

Important Dates

• November 12, 2005: Abstracts due
• November 27, 2005: Notification of paper acceptance
• December 11, 2005: Workshop gathering and presentations (Sunday)

What to Submit: Please send an abstract (up to one page in 11
pt. font) describing your work in either PDF, Postscript, or MS-Word
format.

How to Submit: Email your submission to: David Breitgand
(davidbr[at]il.ibm.com), Gregory Chockler (chockler[at]il.ibm.com), Eyal
Gordon (gordon[at]il.ibm.com)

Workshop Organizers: Alain Azagury (azagury[at]il.ibm.com), David
Breitgand (davidbr[at]il.ibm.com), Gregory Chockler
(chockler[at]il.ibm.com), Amiram Hayardeny (amiram[at]il.ibm.com), Eyal
Gordon (gordon[at]il.ibm.com), Hillel Kolodner (kolodner[at]il.ibm.com),
Kalman Meth (meth[at]il.ibm.com), Yaron Wolfsthal
(wolfstal[at]il.ibm.com)